1. Technical Field
The present invention relates to a crusher which can facilitate cleaning of crush debris, reduce cleaning time and prevent crush debris from remaining in the crusher.
2. Description of Related Art
Creation of a recycling society has been of increasing importance in order to solve problems such as environmental pollution or increased industrial waste. For example, in a molding plant for producing molded articles or molded components using synthetic resin typified by plastic, unwanted parts referred to as sprue runners or defective moldings, which are generated in molding, are collected so as to enhance the resources recycling rate of resin material.
For recycling of resin material, collected sprue runners are crushed by a crusher into crush debris having a predetermined size and used as recycle resources. Such a crusher first roughly crushes sprue runners, which have been introduced from an inlet hopper, with a rough crush blade so that the sprue runners can easily be bitten by a crush blade, and then crushes the roughly crushed material with a crush blade into crush debris having a predetermined pellet shape. A single-shaft type crusher, in which a rough crush blade and a crush blade are fixed at one rotating shaft, is composed of a small number of drive components for driving the rotating shaft and has a simple structure, and therefore is utilized in a large number of establishments aiming at in-house recycle.
On the other hand, when material to be crushed is changed, it is necessary to eliminate crush debris remaining in the crusher every time the material is changed, in order to prevent mixing of different materials. It is necessary to detach the rough crush blade and the crush blade or the like for disassembly and cleaning in order to clean the inner part of the crusher, since crush debris remains at a variety of places, such as clearance of a crush blade provided with a blade edge having a complicated shape, the surrounding area of a rough crush blade, or the inner side of a rough crush blade cover for preventing discharge of material roughly crushed by the rough crush blade. Such cleaning task is difficult and requires a fair amount of time. Consequently, a crusher having a double swing structure at a pair of surfaces of a casing body for covering a rough crush blade and a crush blade has been produced in order to reduce cleaning time and facilitate the cleaning task.
FIG. 12 is a schematic side view for illustrating an essential part of a conventional crusher. The crusher has a substantially box-shaped structure. A pair of fixed side walls 52, 52 are arranged away from each other at one opposed positions of a substantially box-shaped body, and a rotating shaft 60 is laid between substantially central parts of the respective fixed side walls 52. The rotating shaft 60 is fitted with a plurality of rough crush blades 54, . . . provided at predetermined intervals and arrangement, and with crush blades 56, . . . arranged between the fixed side walls 52 and the rough crush blades 54 and between the rough crush blades 54. It is to be noted that the orbit of the tip parts of the rough crush blades 54 and crush blades 56 are drawn in broken lines in the figure. A pair of rocking side walls 53, 53 are arranged at the other opposed positions of the substantially box-shaped body so as to be able to rock around rocking shafts 62, 62 which are parallel to the rotating shaft 60. The respective fixed side walls 52 and the respective rocking side walls 53 make up a casing.
At the inner side of one rocking side wall 53, a fixed blade 57, which is composed of a plurality of first fixed blades 57a, . . . and a second fixed blade 57b, is fixed at a predetermined position. The first fixed blades 57a mainly crush sprue runners into crush debris having a predetermined pellet size in cooperation with the crush blades 56, and the second fixed blade 57b makes it easy for the sprue runners to be bitten by the crush blades 56, in cooperation with the rough crush blades 54. Moreover, at the inner side of the rocking side wall 53, a rough crush blade cover 61 for preventing discharge of material roughly crushed by the rough crush blades 54 is provided. The rough crush blade cover 61 forms arcuate space inside thereof so as to cover the rotation orbit of the rough crush blades 54. At the inner side of the other rocking side wall 53, a scraper 55 for scraping and discharging crush debris crushed by the crush blades 56 is fixed at a predetermined position and a rough crush blade cover 61 is provided.
By rotating the rocking side walls 53 about the rocking shafts 62 for a closing operation with handles 64, contact surfaces 61a of the respective rough crush blade covers 61 come into contact with each other, preventing discharge of material roughly crushed by the rough crush blades 54. Moreover, by rotating the rocking side walls 53 about the rocking shafts 62 and supporting the rocking side walls 53 with supporting members 63, a double swing structure of the casing body is realized. With such a structure, it becomes possible to achieve the cleaning task without detaching the rough crush blades 54 and the crush blades 56 or the like for disassembly.
Moreover, produced is a chopping machine (crusher), maintenance of which can be performed easily with a structure wherein a rough crush blade cover is separated into a rough crush blade cover fixed at a rocking side wall and a rough crush blade casing detachable from a rocking side wall, the detachable rough crush blade casing (an intermediate member of a rough crush blade cover) is placed at the lower side of the rotating shaft, and the rough crush blade casing is supported with a clamp cam (see, Japanese Patent Application Laid-Open No. 2004-105863).